NOTHAMUSIUM. 1 59 



Place, Stonyhurst (Lancashire), and stream running into River Wharf, Burnsall, 

 Yorkshire. 



Observations. — This beautiful specimen was found by the Rev. Charles Hildreth, 

 S.J., who has most kindly presented it to the Museum of Practical Geology, 

 Jermyn Street. The specimen is that of a perfect left valve, evidently a full- 

 grown example, somewhat crushed along the hinge-line. The gradually tapering- 

 posterior end and general shape point to the genus Solenomorpha, to which I now 

 refer it without hesitation. S. major is so much larger, more compressed, and 

 deeper than 8. 'minor, that there is no danger of the two species being confused. 

 Some half dozen specimens have been obtained from Hodder Place. 



I have described and figured two species of Solenomorpha in my ' Monograph of 

 the Carboniferous Lamellibranchiata,' vol i, pt. v (1900), pp. 413 — 14 (Paleeont. 

 Soc, vol. liv). At that time I had unfortunately very poor material for study and 

 illustration of 8. minor and 8. 'parallel a, the two species described. I have since 

 obtained a very fine, almost complete, example of 8. minor, from the Carboniferous 

 Limestone of Yeat-House Quarry, near Frizington (Cumberland), which is figured 

 here (PI. XXII, fig. 3), to compare with 8. major. In this specimen, which is a 

 cast of the interior, the anterior adductor muscle-scar is well shown, and also the 

 broad upper surface of the shell, with a parallel groove on each side of the hinge- 

 line. 



The Shales of Hodder Place have yielded an interesting fauna. I have recog- 

 nised in them the following organisms: Phillipsia Van tier Grachtii; Phillipsia 

 Polleni; Prolecanites compressus ; Glyphioceras spirale,; Glyphioceras reticulatum ; 

 Glyphioceras platylohum ; Orthoceras annuloso-lineatum ; Posidonomya Becheri; 

 Solenomorpha major. Also a few brachiopods and Zaphrentoid corals. 



I do not think that the beds can be very far above the top of the Massive Lime- 

 stone, a fact indicated by the presence of Prolecanites compressus and Posidonomya 

 Becheri. 



Genus Nothamusium, novum. 



Generic Characters. — Shell of medium size, equivalve, very inequilateral, 

 obliquely ovate, moderately convex. The anterior end gaping and short. The 

 anterior margin is acutely pointed above ; it becomes concave as it descends, 

 and then broadly convex. The inferior margin is gently convex, the posterior 

 elliptically rounded. The hinge-line is straight in front, sloping downwards 

 behind the umbo. The umbo is small, pointed, twisted forwards, very slightly 

 raised, placed at the junction of the anterior and middle thirds of the hinge-line. 



